Extended Wear Electrocardiography Patch With Wire Contact Surfaces

ABSTRACT

Physiological monitoring can be provided through a wearable monitor that includes a flexible extended wear electrode patch and a removable reusable monitor recorder. A pair of flexile wires is interlaced or sewn into a flexible backing, serving as electrode signal pickup and electrode circuit traces. The wearable monitor sits centrally on the patient&#39;s chest along the sternum, which significantly improves the ability to sense cutaneously cardiac electric signals, particularly those generated by the atrium. The electrode patch is shaped to fit comfortably and conformal to the contours of the chest approximately centered on the sternal midline. To counter the dislodgment due to compressional and torsional forces, non-irritating adhesive is provided on the underside, or contact, surface of the electrode patch, but only on the distal and proximal ends. Interlacing or sewing the flexile wires into the flexile backing also provides structural support and malleability against compressional, tensile and torsional forces.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional patent application is a continuation of U.S. patentapplication Ser. No. 14/463,585, filed Aug. 19, 2014, pending, which isa continuation-in-part of U.S. Pat. No. 9,545,204, issued Jan. 17, 2017,and further claims priority under 35 U.S.C. §119(e) to U.S. ProvisionalPatent application, Ser. No. 61/882,403, filed Sep. 25, 2013, thedisclosures of which are incorporated by reference.

FIELD

This application relates in general to electrocardiographic monitoringand manufacture and, in particular, to an extended wearelectrocardiography patch with wire contact surfaces.

BACKGROUND

An electrocardiogram (ECG) is a tool used by physicians to diagnoseheart problems and other potential health concerns. A full 12-lead ECGprovides a multi-vector snapshot of heart function, typically recordedover 12 seconds, that can help diagnose rate and regularity ofheartbeats, effect of drugs or cardiac devices, including pacemakers andimplantable cardioverter-defibrillators (ICDs), and whether a patienthas heart disease of any sort. Full 12-lead ECGs are used in-clinics orhospitals and, as a result, are limited to recording only thoseheart-related aspects present at the time of recording. Sporadicconditions that may not show up during a 12-second ECG recording requireother means to diagnose them. These sporadic conditions include faintingor syncope; rhythm disorders, such as tachyarrhythmias andbradyarrhythmias; apneic episodes; and other cardiac and relateddisorders. Thus, a 12-lead ECG only provides a partial picture and canbe insufficient for complete patient diagnosis of many cardiacdisorders.

Diagnostic efficacy of problems, like syncope or cardiac arrhythmias,can be improved through the use of long-term extended wear ECGmonitoring. Recording sufficient ECG and related physiological data overan extended period of time remains a significant challenge to healthcareproviders, despite over a 40-year history of such efforts. Extendedperiod monitoring essentially enables a physician to identify cardiacconditions, specifically, rhythm disorders, and other physiologicalevents of potential concern. A 30-day observation day period isconsidered the “gold standard” of ECG monitoring, yet achieving a 30-dayobservation day period has heretofore proven unworkable because such ECGmonitoring systems are arduous to employ, cumbersome to the patient, andexcessively costly to manufacture and deploy. Nevertheless, if apatient's ECG could be recorded in an ambulatory setting over prolongedtime periods, thereby allowing the patient to engage in activities ofdaily living, the chances of acquiring meaningful medical informationand capturing an abnormal event while the patient is engaged in normalactivities becomes more likely to be achieved.

Conventionally, maintaining continual contact between ECG electrodes andthe skin after a day or two has been a problem. Time, dirt, moisture,and other environmental contaminants, as well as perspiration, skin oil,and dead skin cells from the patient's body, can get between an ECGelectrode's non-conductive adhesive and the skin's surface. All of thesefactors adversely affect electrode adhesion and the quality of cardiacsignal recordings. Furthermore, the physical movements of the patientand their clothing impart various compressional, tensile, and torsionalforces on the contact point of an ECG electrode, especially over longrecording times, and an inflexibly fastened ECG electrode will be proneto becoming dislodged. Moreover, dislodgment may occur unbeknownst tothe patient, making the ECG recordings worthless. Further, some patientsmay have skin that is susceptible to itching or irritation, and thewearing of ECG electrodes can aggravate such skin conditions. Thus, apatient may want or need to periodically remove or replace ECGelectrodes during a long-term ECG monitoring period, whether to replacea dislodged electrode, reestablish better adhesion, alleviate itching orirritation, allow for cleansing of the skin, allow for showering andexercise, or for other purpose. Such replacement or slight alteration inelectrode location actually facilitates the goal of recording the ECGsignal for long periods of time.

In addition, the high cost of the patient-wearable components used toprovide long-term extended ECG monitoring can negatively influence theavailability and use of monitors. Ideally, disposable, single-usecomponents, such as adhesive electrodes, should be low cost, while othercomponents of higher complexity, particularly the electronics hardwarethat detects and records ECG and related physiology, may be ofunavoidably higher cost. To a degree, costs can be balanced by designinghigher complexity components to be re-usable, but when the total cost ofa full ECG monitoring ensemble remains high, despite the utilization ofre-usable parts, the number of monitors available for use by healthcareproviders can be inhibited. Cost, then, becomes a barrier to entry,which, in turn, can hinder or prevent healthcare providers fromobtaining the means with which to efficaciously identify the physiologyunderlying sporadic cardiac arrhythmic conditions and can ultimatelycontribute to a failure to make a proper and timely medical diagnosis.

Conventionally, Holter monitors are widely used for long-term extendedECG monitoring. Typically, they are often used for only 24-48 hours. Atypical Holter monitor is a wearable and portable version of an ECG thatinclude cables for each electrode placed on the skin and a separatebattery-powered ECG recorder. The cable and electrode combination (orleads) are placed in the anterior thoracic region in a manner similar towhat is done with an in-clinic standard ECG machine. The duration of aHolter monitoring recording depends on the sensing and storagecapabilities of the monitor, as well as battery life. A “looping” Holter(or event) monitor can operate for a longer period of time byoverwriting older ECG tracings, thence “recycling” storage in favor ofextended operation, yet at the risk of losing event data. Althoughcapable of extended ECG monitoring, Holter monitors are cumbersome,expensive and typically only available by medical prescription, whichlimits their usability. Further, the skill required to properly placethe electrodes on the patient's chest hinders or precludes a patientfrom replacing or removing the precordial leads and usually involvesmoving the patient from the physician office to a specialized centerwithin the hospital or clinic.

The ZIO XT Patch and ZIO Event Card devices, manufactured by iRhythmTech., Inc., San Francisco, Calif., are wearable stick-on monitoringdevices that are typically worn on the upper left pectoral region torespectively provide continuous and looping ECG recording. The locationis used to simulate surgically implanted monitors. Both of these devicesare prescription-only and for single patient use. The ZIO XT Patchdevice is limited to a 14-day monitoring period, while the electrodesonly of the ZIO Event Card device can be worn for up to 30 days. The ZIOXT Patch device combines both electronic recordation components andphysical electrodes into a unitary assembly that adheres to thepatient's skin. The ZIO XT Patch device uses adhesive sufficientlystrong to support the weight of both the monitor and the electrodes overan extended period of time and to resist disadherence from the patient'sbody, albeit at the cost of disallowing removal or relocation during themonitoring period. The ZIO Event Card device is a form of downsizedHolter monitor with a recorder component that must be removedtemporarily during baths or other activities that could damage thenon-waterproof electronics. Both devices represent compromises betweenlength of wear and quality of ECG monitoring, especially with respect toease of long term use, female-friendly fit, and quality of cardiacelectrical potential signals, especially atrial (P-wave) signals.

Therefore, a need remains for a low cost extended wear continuouslyrecording ECG monitor practicably capable of being worn for a longperiod of time, especially in patient's whose breast anatomy caninterfere with signal quality in both men and women and that is capableof recording atrial action potential signals reliably.

SUMMARY

Physiological monitoring can be provided through a lightweight wearablemonitor that includes two components, a flexible extended wear electrodepatch and a reusable monitor recorder that removably snaps into areceptacle on the electrode patch. The wearable monitor sits centrally(in the midline) on the patient's chest along the sternum orientedtop-to-bottom. The placement of the wearable monitor in a location atthe sternal midline (or immediately to either side of the sternum), withits unique narrow “hourglass”-like shape, significantly improves theability of the wearable monitor to cutaneously sense cardiac electricalpotential signals, particularly the P-wave (or atrial activity) and, toa lesser extent, the QRS interval signals indicating ventricularactivity in the ECG waveforms.

The electrode patch is shaped to fit comfortably and conformal to thecontours of the patient's chest approximately centered on the sternalmidline. To counter the dislodgment due to compressional and torsionalforces, a layer of non-irritating adhesive, such as hydrocolloid, isprovided at least partially on the underside, or contact, surface of theelectrode patch, but only on the electrode patch's distal and proximalends, where the electrode signal pickups are located. The unadhesednarrowed midsection rides freely over the skin. To counter dislodgmentdue to tensile and torsional forces, a flexible backing is reinforcedwith a flexile wire interlaced longitudinally through the narrowedmidsection, with the curvature of the flexile wire providing bothstructural support and malleability. Each of these components aredistinctive and allow for comfortable and extended wear, especially forwomen, where breast mobility would otherwise interfere with monitor useand wearer comfort.

Moreover, the interlacing of flexile wire simplifies manufacturing andreduces costs. A simple pair of flexile wires are used, instead ofcustom point-to-point circuit traces, to connect each electrode signalpickup to the receptacle. One end of each flexile wire can be sewn intothe receptacle's circuit board, thereby obviating the need forconductive adhesive, soldered or electromechanical connection, and theother end of each flexile wire, when stripped of insulation, can act asan electrode signal pickup, which lowers component count.

In one embodiment, an extended wear electrocardiography patch with wirecontact surfaces is provided. The patch includes a flexible backingformed of an elongated strip of stretchable material with narrowlongitudinal midsection evenly tapering inward from a distal end and aproximal end, the elongated strip adherable only to a contact surfacedefined on each of the ends; a pair of flexile wires, one of the wiresforming an electrocardiographic electrode, the electrocardiographicelectrode formed by a portion of the one wire that is sewn into thedistal end of the elongated strip and that is configured for directlycontacting the patient, the one wire continuing back along an axial paththrough the midsection, another one of the wires forming anotherelectrocardiographic electrode, the electrocardiographic electrodeformed by a portion of the another wire that is sewn into the proximalend of the elongated strip and that is configured for electricallycontacting the patient, each of the electrodes including an electricallyconductive area only exposed on the contact surface; and a set ofelectrical contact pads included on the flexible backing and formed byfurther flexile wires, one or more of the pads of the set connected tothe electrodes and configured to interface the electrodes with anelectrocardiography monitor recorder.

In a further embodiment, an extended wear interlaced electrocardiographypatch with wire contact surfaces is provided. The patch includes aflexible backing formed of an elongated strip of stretchable materialwith narrow longitudinal midsection evenly tapering inward from a distalend and a proximal end, the elongated strip adherable only to a contactsurface defined on each of the ends; a pair of flexile wires, one of thewires forming an electrocardiographic electrode, theelectrocardiographic electrode formed by a portion of the one wire thatis interlaced into the distal end of the elongated strip and that isconfigured for directly contacting the patient, the one wire continuingback along an axial path through the midsection, another one of thewires forming another electrocardiographic electrode, theelectrocardiographic electrode formed by a portion of the another wirethat is interlaced into the proximal end of the elongated strip and thatis configured for electrically contacting the patient, each of theelectrodes including an electrically conductive area only exposed on thecontact surface; and a set of electrical contact pads included on theflexible backing and formed by further flexile wires, one or more of thepads of the set connected to the electrodes and configured to interfacethe electrodes with an electrocardiography monitor recorder.

In a still further embodiment, an extended wear embedded electrodeelectrocardiography patch with wire contact surfaces is provided. Thepatch includes a flexible backing formed of an elongated strip ofstretchable material with a narrow longitudinal midsection evenlytapering inward from a distal end and a proximal end, the elongatedstrip adherable only to a contact surface defined on each of the ends; adistal electrically conductive adhesive positioned on the distal end andconfigured for directly contacting a patient; a proximal electricallyconductive adhesive positioned on the proximal end and configured fordirectly contacting the patient; a pair of flexile wires, one of thewires forming an electrocardiographic electrode by a portion of the wireembedded within the distal electrically conductive adhesive on thedistal end, the one wire continuing back along an axial path through thenarrow longitudinal midsection, another one of the wires forming anotherelectrocardiographic electrode by a portion of the another wire embeddedwithin the proximal electrically conductive adhesive, wherein theembedded portion of the one wire receives electrical potentials of thepatient directly from the distal electrically conductive adhesive andthe embedded portion of the another wire receives electrical potentialsof the patient directly from the proximal electrically conductiveadhesive; and a set of electrical contact pads included on the flexiblebacking and formed by further flexile wires, one or more of the pads ofthe set connected to the electrodes and configured to interface theelectrodes with an electrocardiography monitor recorder.

The monitoring patch is especially suited to the female anatomy,although also easily used over the male sternum. The narrow longitudinalmidsection can fit nicely within the intermammary cleft of the breastswithout inducing discomfort, whereas conventional patch electrodes arewide and, if adhered between the breasts, would cause chafing,irritation, discomfort, and annoyance, leading to low patientcompliance.

The foregoing aspects enhance ECG monitoring performance and quality byfacilitating long-term ECG recording, which is critical to accuratearrhythmia and cardiac rhythm disorder diagnoses.

In addition, the foregoing aspects enhance comfort in women (and certainmen), but not irritation of the breasts, by placing the monitoring patchin the best location possible for optimizing the recording of cardiacsignals from the atrium, particularly P-waves, which is another featurecritical to proper arrhythmia and cardiac rhythm disorder diagnoses.

Further, the interlaced flexile wires improve the dermal electrode'sresponse to tensile, twisting, compressional, and torsional forces byproviding a strain relief and tensile strength, while also diminish thecost and complexity of producing physiological electrode assemblies andother types of electrical circuits, where point-to-pointinterconnections are needed.

Still other embodiments will become readily apparent to those skilled inthe art from the following detailed description, wherein are describedembodiments by way of illustrating the best mode contemplated. As willbe realized, other and different embodiments are possible and theembodiments' several details are capable of modifications in variousobvious respects, all without departing from their spirit and the scope.Accordingly, the drawings and detailed description are to be regarded asillustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are diagrams showing, by way of examples, an extended wearelectrocardiography monitor, including an extended wear electrode patchin accordance with one embodiment, respectively fitted to the sternalregion of a female patient and a male patient.

FIG. 3 is a perspective view showing an extended wear electrode patch inaccordance with one embodiment with a monitor recorder inserted.

FIG. 4 is a perspective view showing the extended wear electrode patchof FIG. 3 without a monitor recorder inserted.

FIG. 5 is a top view showing the flexible circuit of the extended wearelectrode patch of FIG. 3.

FIG. 6 is a perspective view showing the extended wear electrode patchin accordance with a further embodiment.

FIG. 7 is an exploded view showing the component layers of the electrodepatch of FIG. 3.

FIG. 8 is a bottom plan view of the extended wear electrode patch ofFIG. 3 with liner partially peeled back.

FIG. 9 is a perspective view of an extended wear electrode patch with aflexile wire electrode assembly in accordance with a still furtherembodiment.

FIG. 10 is perspective view of the flexile wire electrode assembly fromFIG. 9, with a layer of insulating material shielding a bare distal wirearound the midsection of the flexible backing.

FIG. 11 is a bottom view of the flexile wire electrode assembly as shownin FIG. 9.

FIG. 12 is a bottom view of a flexile wire electrode assembly inaccordance with a still yet further embodiment.

FIG. 13 is a perspective view showing the longitudinal midsection of theflexible backing of the electrode assembly from FIG. 9.

FIG. 14 is a longitudinal cross-sectional view of the midsection of theflexible backing of the electrode assembly of FIG. 11.

FIGS. 15A-C are the electrode assembly from FIG. 14 under compressional,tensile, and bending force, respectively.

FIG. 16 is a flow diagram showing a method for constructing astress-pliant physiological electrode assembly in accordance with afurther embodiment.

DETAILED DESCRIPTION

Physiological monitoring can be provided through a wearable monitor thatincludes two components, a flexible extended wear electrode patch and aremovable reusable monitor recorder. FIGS. 1 and 2 are diagrams showing,by way of examples, an extended wear electrocardiography monitor 12,including an extended wear electrode patch 15 in accordance with oneembodiment, respectively fitted to the sternal region of a femalepatient 10 and a male patient 11. The wearable monitor 12 sits centrally(in the midline) on the patient's chest along the sternum 13 orientedtop-to-bottom with the monitor recorder 14 preferably situated towardsthe patient's head. The electrode patch 15 is shaped to fit comfortablyand conformal to the contours of the patient's chest approximatelycentered on the sternal midline 16 (or immediately to either side of thesternum 13). The distal end of the electrode patch 15 extends towardsthe Xiphoid process and lower sternum and, depending upon the patient'sbuild, may straddle the region over the Xiphoid process and lowersternum. The proximal end of the electrode patch 15, located under themonitor recorder 14, is below the manubrium and, depending uponpatient's build, may straddle the region over the manubrium.

The placement of the wearable monitor 12 in a location at the sternalmidline 16 (or immediately to either side of the sternum 13)significantly improves the ability of the wearable monitor 12 tocutaneously sense cardiac electric signals, particularly the P-wave (oratrial activity) and, to a lesser extent, the QRS interval signals inthe ECG waveforms that indicate ventricular activity. The sternum 13overlies the right atrium of the heart and the placement of the wearablemonitor 12 in the region of the sternal midline 13 puts the ECGelectrodes of the electrode patch 15 in a location better adapted tosensing and recording P-wave signals than other placement locations,say, the upper left pectoral region. In addition, placing the lower orinferior pole (ECG electrode) of the electrode patch 15 over (or near)the Xiphoid process and lower sternum facilitates sensing of rightventricular activity and provides superior recordation of the QRSinterval.

During use, the electrode patch 15 is first adhered to the skin alongthe sternal midline 16 (or immediately to either side of the sternum13). A monitor recorder 14 is then snapped into place on the electrodepatch 15 to initiate ECG monitoring. FIG. 3 is a perspective viewshowing an extended wear electrode patch 15 in accordance with oneembodiment with a monitor recorder 14 inserted. The body of theelectrode patch 15 is preferably constructed using a flexible backing 20formed as an elongated strip 21 of wrap knit or similar stretchablematerial about 145 mm long and 32 mm at the widest point with a narrowlongitudinal mid-section 23 evenly tapering inward from both sides. Apair of cut-outs 22 between the distal and proximal ends of theelectrode patch 15 create a narrow longitudinal midsection 23 or“isthmus” and defines an elongated “hourglass”-like shape, when viewedfrom above, such as described in commonly-assigned U.S. Design patentapplication, entitled “Extended Wear Electrode Patch,” Ser. No.29/472,045, filed Nov. 7, 2013, pending, the disclosure of which isincorporated by reference. The upper part of the “hourglass” is sized toallow an electrically non-conductive receptacle 25, sits on top of theoutward-facing surface of the electrode patch 15, to be affixed to theelectrode patch 15 with an ECG electrode placed underneath on thepatient-facing underside, or contact, surface of the electrode patch 15;the upper part of the “hourglass” has a longer and wider profile thanthe lower part of the “hourglass,” which is sized primarily to allowjust the placement of an ECG electrode.

The electrode patch 15 incorporates features that significantly improvewearability, performance, and patient comfort throughout an extendedmonitoring period. The entire electrode patch 15 is lightweight inconstruction, which allows the patch to be resilient to disadhesing orfalling off and, critically, to avoid creating distracting discomfort tothe patient, even when the patient is asleep. In contrast, the weight ofa heavy ECG monitor impedes patient mobility and will cause the monitorto constantly tug downwards and press on the patient's body; frequentadjustments by the patient are needed to maintain comfort.

During every day wear, the electrode patch 15 is subjected to pushing,pulling, and torsional movements, including compressional and torsionalforces when the patient bends forward, and tensile and torsional forceswhen the patient leans backwards. To counter these stress forces, theelectrode patch 15 incorporates crimp and strain reliefs, as furtherdescribed infra respectively with reference to FIGS. 4 and 5. Inaddition, the cut-outs 22 and longitudinal midsection 23 help minimizeinterference with and discomfort to breast tissue, particularly in women(and gynecomastic men). The cut-outs 22 and longitudinal midsection 23allow better conformity of the electrode patch 15 to sternal bowing andto the narrow isthmus of flat skin that can occur along the bottom ofthe intermammary cleft between the breasts, especially in buxom women.The cut-outs 22 and longitudinal midsection 23 help the electrode patch15 fit nicely between a pair of female breasts in the intermammarycleft. In one embodiment, the cut-outs 22 can be graduated to form thelongitudinal midsection 23 as a narrow in-between stem or isthmusportion about 7 mm wide. In a still further embodiment, tabs 24 canrespectively extend an additional 8 mm to 12 mm beyond the distal andproximal ends of the flexible backing 20 to facilitate purchase whenadhering the electrode patch 15 to or removing the electrode patch 15from the sternum 13. These tabs preferably lack adhesive on theunderside, or contact, surface of the electrode patch 15. Still othershapes, cut-outs and conformities to the electrode patch 15 arepossible.

The monitor recorder 14 removably and reusably snaps into anelectrically non-conductive receptacle 25 during use. The monitorrecorder 14 contains electronic circuitry for recording and storing thepatient's electrocardiography as sensed via a pair of ECG electrodesprovided on the electrode patch 15, such as described incommonly-assigned U.S. patent application, entitled “Extended WearAmbulatory Electrocardiography and Physiological Sensor Monitor,” Ser.No. 14/080,725, filed Nov. 14, 2013, pending, the disclosure of which isincorporated by reference. The circuitry includes a microcontroller,flash storage, ECG signal processing, analog-to-digital conversion(where applicable), and an external interface for coupling to theelectrode patch 15 and to a download station for stored data downloadand device programming. The monitor recorder 14 also includes externalpatient-interfaceable controls, such as a push button to facilitateevent marking and provide feedback. In a further embodiment, thecircuitry, with the assistance of the appropriate types of deployedelectrodes or sensors, is capable of monitoring other types ofphysiology, in addition to ECGs. Still other types of monitor recordercomponents and functionality are possible.

The non-conductive receptacle 25 is provided on the top surface of theflexible backing 20 with a retention catch 26 and tension clip 27 moldedinto the non-conductive receptacle 25 to conformably receive andsecurely hold the monitor recorder 14 in place. The edges of the bottomsurface of the non-conductive receptacle 25 are preferably rounded, andthe monitor recorder 14 is nestled inside the interior of thenon-conductive receptacle 25 to present a rounded (gentle) surface,rather than a sharp edge at the skin-to-device interface.

The electrode patch 15 is intended to be disposable. The monitorrecorder 14, however, is reusable and can be transferred to successiveelectrode patches 15 to ensure continuity of monitoring. The placementof the wearable monitor 12 in a location at the sternal midline 16 (orimmediately to either side of the sternum 13) benefits long-termextended wear by removing the requirement that ECG electrodes becontinually placed in the same spots on the skin throughout themonitoring period. Instead, the patient is free to place an electrodepatch 15 anywhere within the general region of the sternum 13.

As a result, at any point during ECG monitoring, the patient's skin isable to recover from the wearing of an electrode patch 15, whichincreases patient comfort and satisfaction, while the monitor recorder14 ensures ECG monitoring continuity with minimal effort. A monitorrecorder 14 is merely unsnapped from a worn out electrode patch 15, theworn out electrode patch 15 is removed from the skin, a new electrodepatch 15 is adhered to the skin, possibly in a new spot immediatelyadjacent to the earlier location, and the same monitor recorder 14 issnapped into the new electrode patch 15 to reinitiate and continue theECG monitoring.

During use, the electrode patch 15 is first adhered to the skin in thesternal region. FIG. 4 is a perspective view showing the extended wearelectrode patch 15 of FIG. 3 without a monitor recorder 14 inserted. Aflexible circuit 32 is adhered to each end of the flexible backing 20. Adistal circuit trace 33 from the distal end 30 of the flexible backing20 and a proximal circuit trace (not shown) from the proximal end 31 ofthe flexible backing 20 electrically couple ECG electrodes (not shown)with a pair of electrical pads 34. In a further embodiment, the distaland proximal circuit traces are replaced with interlaced or sewn-inflexible wires, as further described infra beginning with reference toFIG. 9. The electrical pads 34 are provided within a moisture-resistantseal 35 formed on the bottom surface of the non-conductive receptacle25. When the monitor recorder 14 is securely received into thenon-conductive receptacle 25, that is, snapped into place, theelectrical pads 34 interface to electrical contacts (not shown)protruding from the bottom surface of the monitor recorder 14. Themoisture-resistant seal 35 enables the monitor recorder 14 to be worn atall times, even during bathing or other activities that could expose themonitor recorder 14 to moisture or adverse conditions.

In addition, a battery compartment 36 is formed on the bottom surface ofthe non-conductive receptacle 25. A pair of battery leads (not shown)from the battery compartment 36 to another pair of the electrical pads34 electrically interface the battery to the monitor recorder 14. Thebattery contained within the battery compartment 35 can be replaceable,rechargeable or disposable.

The monitor recorder 14 draws power externally from the battery providedin the non-conductive receptacle 25, thereby uniquely obviating the needfor the monitor recorder 14 to carry a dedicated power source. Thebattery contained within the battery compartment 36 can be replaceable,rechargeable or disposable. In a further embodiment, the ECG sensingcircuitry of the monitor recorder 14 can be supplemented with additionalsensors, including an SpO₂ sensor, a blood pressure sensor, atemperature sensor, respiratory rate sensor, a glucose sensor, an airflow sensor, and a volumetric pressure sensor, which can be incorporateddirectly into the monitor recorder 14 or onto the non-conductivereceptacle 25.

The placement of the flexible backing 20 on the sternal midline 16 (orimmediately to either side of the sternum 13) also helps to minimize theside-to-side movement of the wearable monitor 12 in the left- andright-handed directions during wear. However, the wearable monitor 12 isstill susceptible to pushing, pulling, and torqueing movements,including compressional and torsional forces when the patient bendsforward, and tensile and torsional forces when the patient leansbackwards. To counter the dislodgment of the flexible backing 20 due tocompressional and torsional forces, a layer of non-irritating adhesive,such as hydrocolloid, is provided at least partially on the underside,or contact, surface of the flexible backing 20, but only on the distalend 30 and the proximal end 31. As a result, the underside, or contactsurface of the longitudinal midsection 23 does not have an adhesivelayer and remains free to move relative to the skin. Thus, thelongitudinal midsection 23 forms a crimp relief that respectivelyfacilitates compression and twisting of the flexible backing 20 inresponse to compressional and torsional forces. Other forms of flexiblebacking crimp reliefs are possible.

Unlike the flexible backing 20, the flexible circuit 32 is only able tobend and cannot stretch in a planar direction. FIG. 5 is a top viewshowing the flexible circuit 32 of the extended wear electrode patch 15of FIG. 3. A distal ECG electrode 38 and proximal ECG electrode 39 arerespectively coupled to the distal and proximal ends of the flexiblecircuit 32 to serve as electrode signal pickups. The flexible circuit 32preferably does not extend to the outside edges of the flexible backing20, thereby avoiding gouging or discomforting the patient's skin duringextended wear, such as when sleeping on the side. During wear, the ECGelectrodes 38, 39 must remain in continual contact with the skin. Astrain relief 40 is defined in the flexible circuit 32 at a locationthat is partially underneath the battery compartment 36 when theflexible circuit 32 is affixed to the flexible backing 20. The strainrelief 40 is laterally extendable to counter dislodgment of the ECGelectrodes 38, 39 due to tensile and torsional forces. A pair of strainrelief cutouts 41 partially extend transversely from each opposite sideof the flexible circuit 32 and continue longitudinally towards eachother to define in ‘S’-shaped pattern, when viewed from above. Thestrain relief respectively facilitates longitudinal extension andtwisting of the flexible circuit 32 in response to tensile and torsionalforces. Other forms of circuit board strain relief are possible.

The flexible circuit 32 can be provided either above or below theflexible backing 20. FIG. 6 is a perspective view showing the extendedwear electrode patch 15 in accordance with a further embodiment. Theflexible circuit (not shown) is provided on the underside, or contact,surface of the flexible backing 20 and is electrically interfaced to theset of electrical pads 34 on the bottom surface of the non-conductivereceptacle 25 through electrical contacts (not shown) pierced throughthe flexible backing 20.

The electrode patch 15 is intended to be a disposable component, whichenables a patient to replace the electrode patch 15 as needed throughoutthe monitoring period, while maintaining continuity of physiologicalsensing through reuse of the same monitor recorder 14. FIG. 7 is anexploded view showing the component layers of the electrode patch 15 ofFIG. 3. The flexible backing 20 is constructed of a wearable gauze,latex, woven textile, or similar wrap knit or stretchable and wear-safematerial 44, such as a Tricot-type linen with a pressure sensitiveadhesive (PSA) on the underside, or contact, surface. The ends of thewearable material 44 are coated with a layer 43 of non-irritatingadhesive, such as hydrocolloid, to facilitate long-term wear, while theunadhesed narrowed midsection rides freely over the skin. Thehydrocolloid, for instance, is typically made of mineral oil, celluloseand water and lacks any chemical solvents, so should cause littleitching or irritation. Moreover, hydrocolloid can be manufactured intoan appropriate thickness and plasticity and provides cushioning betweenthe relatively rigid and unyielding non-conductive receptacle 25 and thepatient's skin. In a further embodiment, the layer of non-irritatingadhesive can be contoured, such as by forming the adhesive with aconcave or convex cross-section; surfaced, such as through stripes orcrosshatches of adhesive, or by forming dimples in the adhesive'ssurface; or applied discontinuously, such as with a formation ofdiscrete dots of adhesive.

As described supra with reference to FIG. 5, a flexible circuit can beadhered to either the outward facing surface or the underside, orcontact, surface of the flexible backing 20. For convenience, a flexiblecircuit 47 is shown relative to the outward facing surface of thewearable material 44 and is adhered respectively on a distal end by adistal electrode seal 45 and on a proximal end by a proximal electrodeseal 45. In a further embodiment, the flexible circuit 47 can beprovided on the underside, or contact, surface of the wearable material44. Through the electrode seals, only the distal and proximal ends ofthe flexible circuit 47 are attached to the wearable material 44, whichenables the strain relief 40 (shown in FIG. 5) to respectivelylongitudinally extend and twist in response to tensile and torsionalforces during wear. Similarly, the layer 43 of non-irritating adhesiveis provided on the underside, or contact, surface of the wearablematerial 44 only on the proximal and distal ends, which enables thelongitudinal midsection 23 (shown in FIG. 3) to respectively bow outwardand away from the sternum 13 or twist in response to compressional andtorsional forces during wear.

A pair of openings 46 is defined on the distal and proximal ends of thewearable material 44 and layer 43 of non-irritating adhesive for ECGelectrodes 38, 39 (shown in FIG. 5). The openings 46 serve as “gel”wells with a layer of hydrogel 41 being used to fill the bottom of eachopening 46 as a conductive material that aids electrode signal capture.The entire underside, or contact, surface of the flexible backing 20 isprotected prior to use by a liner layer 40 that is peeled away, as shownin FIG. 8.

The non-conductive receptacle 25 includes a main body 54 that is moldedout of polycarbonate, ABS, or an alloy of those two materials to providea high surface energy to facilitate adhesion of an adhesive seal 53. Themain body 54 is attached to a battery printed circuit board 52 by theadhesive seal 53 and, in turn, the battery printed circuit board 52 isadhered to the flexible circuit 47 with an upper flexible circuit seal50. A pair of conductive transfer adhesive points 51 or, alternatively,soldered connections, or electromechanical connections, includingmetallic rivets or similar conductive and structurally unifyingcomponents, connect the circuit traces 33, 37 (shown in FIG. 5) of theflexible circuit 47 to the battery printed circuit board 52. The mainbody 54 has a retention catch 26 and tension clip 27 (shown in FIG. 3)that fixably and securely receive a monitor recorder 14 (not shown), andincludes a recess within which to circumferentially receive a die cutgasket 55, either rubber, urethane foam, or similar suitable material,to provide a moisture resistant seal to the set of pads 34. Other typesof design, arrangement, and permutation are possible.

In a still further embodiment, the flexible circuit 32 (shown in FIG. 4)and distal ECG electrode 38 and proximal ECG electrode 39 (shown in FIG.5) are replaced with a pair of interlaced flexile wires. The interlacingof flexile wires through the flexible backing 20 reduces bothmanufacturing costs and environmental impact, as further describedinfra. The flexible circuit and ECG electrodes are replaced with a pairof flexile wires that serve as both electrode circuit traces andelectrode signal pickups. FIG. 9 is a perspective view of an extendedwear electrode patch 15 with a flexile wire electrode assembly inaccordance with a still further embodiment. The flexible backing 20maintains the unique narrow “hourglass”-like shape that aids long termextended wear, particularly in women, as described supra with referenceto FIG. 3. For clarity, the non-conductive receptacle 25 is omitted toshow the exposed battery printed circuit board 62 that is adheredunderneath the non-conductive receptacle 25 to the proximal end 31 ofthe flexible backing 20. Instead of employing flexible circuits, a pairof flexile wires are separately interlaced or sewn into the flexiblebacking 20 to serve as circuit connections for an anode electrode leadand for a cathode electrode lead.

To form a distal electrode assembly, a distal wire 61 is interlaced intothe distal end 30 of the flexible backing 20, continues along an axialpath through the narrow longitudinal midsection of the elongated strip,and electrically connects to the battery printed circuit board 62 on theproximal end 31 of the flexible backing 20. The distal wire 61 isconnected to the battery printed circuit board 62 by stripping thedistal wire 61 of insulation, if applicable, and interlacing or sewingthe uninsulated end of the distal wire 61 directly into an exposedcircuit trace 63. The distal wire-to-battery printed circuit boardconnection can be made, for instance, by back stitching the distal wire61 back and forth across the edge of the battery printed circuit board62. Similarly, to form a proximal electrode assembly, a proximal wire(not shown) is interlaced into the proximal end 31 of the flexiblebacking 20. The proximal wire is connected to the battery printedcircuit board 62 by stripping the proximal wire of insulation, ifapplicable, and interlacing or sewing the uninsulated end of theproximal wire directly into an exposed circuit trace 64. The resultingflexile wire connections both establish electrical connections and helpto affix the battery printed circuit board 62 to the flexible backing20.

The battery printed circuit board 62 is provided with a batterycompartment 36. A set of electrical pads 34 are formed on the batteryprinted circuit board 62. The electrical pads 34 electrically interfacethe battery printed circuit board 62 with a monitor recorder 14 whenfitted into the non-conductive receptacle 25. The battery compartment 36contains a spring 65 and a clasp 66, or similar assembly, to hold abattery (not shown) in place and electrically interfaces the battery tothe electrical pads 34 through a pair battery leads 67 for powering theelectrocardiography monitor 14. Other types of battery compartment arepossible. The battery contained within the battery compartment 36 can bereplaceable, rechargeable, or disposable.

In a yet further embodiment, the circuit board and non-conductivereceptacle 25 are replaced by a combined housing that includes a batterycompartment and a plurality of electrical pads. The housing can beaffixed to the proximal end of the elongated strip through theinterlacing or sewing of the flexile wires or other wires or threads.

The core of the flexile wires may be made from a solid, stranded, orbraided conductive metal or metal compounds. In general, a solid wirewill be less flexible than a stranded wire with the same totalcross-sectional area, but will provide more mechanical rigidity than thestranded wire. The conductive core may be copper, aluminum, silver, orother material. The pair of the flexile wires may be provided asinsulated wire. In one embodiment, the flexile wires are made from amagnet wire from Belden Cable, catalogue number 8051, with a solid coreof AWG 22 with bare copper as conductor material and insulated bypolyurethane or nylon. Still other types of flexile wires are possible.In a further embodiment, conductive ink or graphene can be used to printelectrical connections, either in combination with or in place of theflexile wires.

In a still further embodiment, the flexile wires are uninsulated. FIG.10 is perspective view of the flexile wire electrode assembly from FIG.9, with a layer of insulating material 69 shielding a bare uninsulateddistal wire 61 around the midsection on the contact side of the flexiblebacking. On the contact side of the proximal and distal ends of theflexible backing, only the portions of the flexile wires serving aselectrode signal pickups are electrically exposed and the rest of theflexile wire on the contact side outside of the proximal and distal endsare shielded from electrical contact. The bare uninsulated distal wire61 may be insulated using a layer of plastic, rubber-like polymers, orvarnish, or by an additional layer of gauze or adhesive (ornon-adhesive) gel. The bare uninsulated wire 61 on the non-contact sideof the flexible backing may be insulated or can simply be leftuninsulated.

Both end portions of the pair of flexile wires are typically placeduninsulated on the contact surface of the flexible backing 20 to form apair of electrode signal pickups. FIG. 11 is a bottom view of theflexile wire electrode assembly as shown in FIG. 9. When adhered to theskin during use, the uninsulated end portions of the distal wire 61 andthe proximal wire 71 enable the monitor recorder 14 to measure dermalelectrical potential differentials. At the proximal and distal ends ofthe flexible backing 20, the uninsulated end portions of the flexilewires may be configured into an appropriate pattern to provide anelectrode signal pickup, which would typically be a spiral shape formedby guiding the flexile wire along an inwardly spiraling pattern. Thesurface area of the electrode pickups can also be variable, such as byselectively removing some or all of the insulation on the contactsurface. For example, an electrode signal pickup arranged by sewinginsulated flexile wire in a spiral pattern could have a crescent-shapedcutout of uninsulated flexile wire facing towards the signal source.

In a still yet further embodiment, the flexile wires are left freelyriding on the contact surfaces on the distal and proximal ends of theflexible backing, rather than being interlaced into the ends of theflexible backing 20. FIG. 12 is a bottom view of a flexile wireelectrode assembly in accordance with a still yet further embodiment.The distal wire 61 is interlaced onto the midsection and extends anexposed end portion 72 onto the distal end 30. The proximal wire 71extends an exposed end portion 73 onto the proximal end 31. The exposedend portions 72 and 73, not shielded with insulation, are furtherembedded within an electrically conductive adhesive 81. The adhesive 81makes contact to skin during use and conducts skin electrical potentialsto the monitor recorder 14 (not shown) via the flexile wires. Theadhesive 81 can be formed from electrically conductive, non-irritatingadhesive, such as hydrocolloid.

The distal wire 61 is interlaced or sewn through the longitudinalmidsection of the flexible backing 20 and takes the place of theflexible circuit 32. FIG. 13 is a perspective view showing thelongitudinal midsection of the flexible backing of the electrodeassembly from FIG. 9. Various stitching patterns may be adopted toprovide a proper combination of rigidity and flexibility. In simplestform, the distal wire 61 can be manually threaded through a plurality ofholes provided at regularly-spaced intervals along an axial path definedbetween the battery printed circuit board 62 (not shown) and the distalend 30 of the flexible backing 20. The distal wire 61 can be threadedthrough the plurality of holes by stitching the flexile wire as a single“thread.” Other types of stitching patterns or stitching of multiple“threads” could also be used, as well as using a sewing machine orsimilar device to machine-stitch the distal wire 61 into place, asfurther described infra. Further, the path of the distal wire 61 neednot be limited to a straight line from the distal to the proximal end ofthe flexible backing 20.

The distal wire 61 is flexile yet still retains a degree of rigiditythat is influenced by wire gauge, composition, stranding, insulation,and stitching pattern. For example, rigidity decreases with wire gauge;and a solid core wire tends to be more rigid than a stranded core of thesame gauge. The combination of the flexibility and the rigidity of theportion of the distal wire 61 located on or close to the midsectioncontributes to the overall strength and wearability of the patch. FIG.14 is a longitudinal cross-sectional view of the midsection of theflexible backing 20 of the electrode assembly of FIG. 11. FIGS. 15A-Care the electrode assembly from FIG. 14 under compressional, tensile,and bending force, respectively. The relative sizes of the distal wire61 and flexible backing 20 are not to scale and are exaggerated forpurposes of illustration.

The interlacing of the distal wire 61 through the narrow longitudinalmidsection 22 of the flexible backing 20 bends the distal wire 61 into aline of rounded stitches that alternate top and bottom, which can beadvantageous to long term wearability. First, the tension of the roundedstitches reinforces the planar structure of the narrow longitudinalmidsection 22 and spreads a dislodging force impacting on one end of theflexible backing 20 to the other end of the flexible backing 20. Second,the rounded stitches leave room for stretching, compressing, bending,and twisting, thus increasing the wearability of the patch extended wearelectrode patch 15 by facilitating extension, compression, bending, andtwisting of the narrow longitudinal midsection 22 in response totensile, compressional, bending, and torsional forces.

In a further embodiment, the distal wire and the proximal wire may bestitched or sewn into the flexible backing 20. Depending upon the typeof stitching used, the distal or proximal wire may use more than oneindividual wire. For instance, a conventional sewing machine used tostitch fabrics uses a spool of thread and a bobbin, which are both woundwith thread that together allow the creation of various stitchingpatterns, such as the lockstitch. Other type of stitching patterns arepossible. Additionally, where more than one “threads” are used forstitching, the flexile wire may constitute all of the “threads,” therebyincreasing redundancy of the circuit trace thus formed. Alternatively,just one (or fewer than all) of the threads may be conductive, with thenon-conductive threads serving to reinforce the strength of the flexilewire connections and flexible backing 20. The additional threads can bemade from line, threads, or fabrics of sufficient mechanical strengthand do not need to be conductive; alternatively, the same flexile wirescan be employed to serve as the additional threads.

Conventionally, flexible circuits, such as the flexible circuit 32(shown in FIG. 4) that connects the distal ECG electrode 38 and proximalECG electrode 39 (shown in FIG. 5) to the battery printed circuit board62 (shown in FIG. 9), are constructed using subtractive processes. Ingeneral, a flexible circuit interconnects electronic components withcustom point-to-point circuit traces and is typically constructed byforming the conductive circuit traces on a thin film of insulatingpolymer. A flexible circuit is not an off-the-shelf component; rather,each flexible circuit is designed with a specific purpose in mind.Changes to a flexible circuit's design will generally requirefabricating entirely new flexible circuits, as the physical circuittraces on the polymer film cannot be changed.

Manufacturing a flexible circuit typically requires the use ofsophisticated and specialized tools, coupled with environmentallyunfriendly processes, including depositing copper on a polyamide core,etching away unwanted copper with inline etching or an acid bath toretain only the desired conductive circuit traces, and applying acoverlay to the resulting flexible circuit. Significant amounts ofhazardous waste are generated by these subtractive processes during thefabrication of each flexible circuit. Properly disposing of suchhazardous waste is expensive and adds to the costs of the flexiblecircuit.

In the still further embodiment described supra beginning with referenceto FIG. 9, the distal and proximal flexile wires replace the flexiblecircuit 32 and enables the electrode assembly to be constructed usingadditive processes with off-the-shelf, low cost components. The flexilewires serve the triple functions of an electrode signal pickup,electrical circuit trace, and support for structural integrity andmalleability of the electrode assembly.

The general manner of constructing the electrode assembly can be appliedto other forms of electronic components in which custom point-to-pointcircuit traces need to be affixed to a gauze or textile backing, as wellas backings made from other materials. The circuit traces are replacedby the interlaced or sewn flexile wires, and the ends of each flexilewire are terminated, as appropriate to the application. The flexilewires may, by example, connect two circuit boards, or connect to anelectrical terminal, power source, or electrical component. In addition,flexile wires may be used to replace a printed circuit board entirely,with each flexile wire serving as a form of sewn interconnect betweentwo or more discrete components, including resistors, capacitors,transistors, diodes, operational amplifiers (op amps) and otherintegrated circuits, and other electronic or electromechanicalcomponents.

By way of illustration, the flexile wires will be described asterminated for use in an electrode assembly, specifically, as terminatedon one end to form an electrode signal pickup and on the other end toconnect into a circuit board. Constructing the electrode assemblyentails interlacing, including manually threading, or machine sewing theflexile, conductive wire through the flexible backing 20. FIG. 16 is aflow diagram showing a method 90 for constructing a stress-pliantphysiological electrode assembly in accordance with a furtherembodiment. The method can be performed by a set of industrial machines,including a gauze cutting machine to cut the flexible backing 20 toform; a hole punch to cut a plurality of holes provided atregularly-spaced intervals; a stitching or sewing machine to interleaveor sew the flexile wire through the flexible backing 20; a wire stripperor plasma jet to remove insulation from the flexile wire, whenapplicable; and a glue or adhesive dispenser to embed or coat electrodesignal pickup in hydrocolloid gel or equivalent non-irritating adhesive.Other forms or combinations of industrial machines, including a singlepurpose-built industrial machine, could be used.

As an initial step, a backing is cut to shape and, if required, holesare cut at regularly-spaced intervals along an axial path (step 91)through which the flexile wire will be interlaced. Holes will need to becut, for instance, if the flexile wire is to be hand-guided through thebacking, or where the backing is cut from a material that is difficultto puncture with a threaded needle, such as used by a sewing machine. Inone embodiment, the backing is cut from wearable gauze, latex, woventextile, or similar wrap knit or stretchable and wear-safe material,such as a Tricot-type linen; the resulting backing is flexible andyielding. The backing is also cut into an elongated “hourglass”-likeshape, when viewed from above, with a pair of cut-outs and alongitudinal midsection that together help minimize interference withand discomfort to breast tissue, particularly in women (and gynecomasticmen), such as described supra with reference to FIG. 3. The backing canbe cut into other shapes as appropriate to need. In addition, dependingupon the application, other materials could be substituted for thebacking. For example, neoprene, such as used in wetsuits, could be usedwhere a high degree of elasticity and ruggedness is desired.

The flexile wire is then interlaced or sewn into the backing (step 92).Interlacing can be performed by a machine that guides the flexile wirethrough the holes previously cut in the material in a crisscrossed,interwoven, or knitted fashion, as well as by hand. The flexile wire canalso be guided through the backing without first cutting holes, providedthat the weave of the material is sufficiently loose to allow passage ofthe flexile wire if the flexile wire is otherwise incapable of passingthrough the backing without the assistance of a needle or other piercinginstrument.

Alternatively, the flexile wire could be sewn into the backing by usingthe flexile wire as “thread” that is stitched into place using a needleor similar implement. If a single flexile wire is employed, thestitching will be a line of rounded stitches that alternate top andbottom, as described supra; however, if more than one flexile wire isused, or the stitching pattern requires the use of more than one thread,other forms of conventional machine-stitching patterns could beemployed, such as a lockstitch.

Once completed, the interlacing or sewing of the flexile wire into thebacking creates an integrated point-to-point electrical path that takesthe place of a custom circuit trace using an additive, rather thansubtractive, manufacturing process. The flexile wire can be interlacedor sewn along a straight, curved, or arbitrary path. One flexile wire isrequired per point-to-point circuit trace. The strength and pliabilityof the flexile wire reinforces the backing and, in the still furtherembodiment described supra beginning with reference to FIG. 9,facilitates extension, compression, bending, and twisting of the narrowlongitudinal midsection 22 in response to tensile, compressional,bending, and torsional forces. Thus, the path of the flexile wire alongthe backing can be mapped to take advantage of the strength andreinforcing properties of the flexile wire, which, when interlaced orsewn into the backing, help the backing counter the stresses to whichthe backing will be subjected when deployed.

The flexile wire itself may be insulated or bare (step 93). When one endof the flexile wire is connected to (or forms) an electrode,particularly a dermal physiology electrode that senses electricalpotentials on the skin's surface, insulated flexile wire will ordinarilybe used, with only a portion of the flexile wire incident to theelectrode stripped of insulation. However, bare uninsulated flexile wirecould alternatively be used throughout, so long as those portions of theuninsulated flexile wire that are exposed on the contact-facing surfaceof the backing are insulated and shielded from electrical contact (step94), such as by applying a layer of plastic, rubber-like polymers, orvarnish, or by an additional layer of gauze or adhesive (ornon-adhesive) gel over the exposed wire. The uninsulated flexile wireexposed on other surfaces of the backing could also be insulated orsimply be left bare.

One end of the flexile wire may be terminated as an electrode signalpickup (step 95). If insulated flexile wire is used, a portion of theend of the flexile wire is stripped of insulation (step 96) using, forinstance, a wire stripper or plasma jet. The electrode signal pickupcould either be formed by interlacing (or sewing) the flexile wire (step97) into the backing in the shape of the desired electrode (step 98) orpositioned over the contact-facing area of the backing designated toserve as an electrode signal pickup and embedded within an electricallyconductive adhesive (step 99). In a yet further embodiment, the flexilewire could be terminated as a connection to a discrete electrode, suchas by sewing an uninsulated portion of the end of the electrode wireinto the discrete electrode to thereby establish an electrical contactand affix the discrete electrode to the backing. The Universal ECG EKGelectrode, manufactured by Bio Protech Inc., Tustin, Calif., is oneexample of a discrete electrode.

Finally, the other end of the flexile wire may be terminated as aconnection to a circuit board (step 100). The flexile wire can beinterlaced or sewn onto the circuit board, for instance, by backstitching the flexile wire back and forth across the edge of the circuitboard to thereby establish an electrical contact and affix the discreteelectrode to the backing.

In a further embodiment, flexile wire can be used to replace all or partof a printed circuit board, such as battery printed circuit board 62used in constructing a stress-pliant physiological electrode assembly,as described supra, or for any other application that requiresinterconnection of electrical or electro mechanical components on aphysical substrate or backing. Flexile wire in place of conductivecircuit traces can work especially well with simple circuit boardlayouts, where ample space between components and relativelyuncomplicated layouts are amenable to stitched-in interconnections. Inaddition, the use of flexile wire can simplify circuit layout design inmultilayer circuits, as insulated flexile wires can be run across eachother in situations that would otherwise require the use of a multilayerprinted circuit board or similar solution.

Through such use of flexile wire, a printed circuit board can be omittedin whole or in part. Interconnects between and connections to theelectronic and electro mechanical components formerly placed on theprinted circuit board can instead be sewn from flexile wire. Forinstance, the battery printed circuit board 62 can be replaced byflexile wire interconnects that connect the electrodes to a sewn set ofelectrical pads formed by over-stitching the flexile wire intoelectrical contact surfaces of sufficient size to interface with amonitor recorder 14 when fitted into the non-conductive receptacle 25.Likewise, the spring 65 and clasp 66 can be sewn in place using flexilewire to hold a battery in place with flexile wire interconnectsconnecting the battery to a sewn set of electrical pads formed byover-stitching the flexile wire into electrical contact surfaces ofsufficient size to interface with a monitor recorder 14 when fitted intothe non-conductive receptacle 25. Still other approaches to replacingprinted circuit boards with flexile wire interconnects are possible.

The resultant stress-pliant physiological electrode assembly may beelectrically coupled to a broad range of physiological monitors notlimited to electrocardiographic measurement. The foregoing method ofconstructing a stress-pliant electrode assembly is adaptable tomanufacturing other forms of dermal electrodes, including electrodes forelectrocardiography, electroencephalography, and skin conductancemeasurements. Further, by adjusting the number of electrodes, thedistances among the electrode signal pickups, and the thickness of theflexile wire, the method can be adapted to manufacturing at low cost anelectrode assembly that is lightweight and resistant to tensile,compressional and torsional forces, thus contributing to long-term wearand versatility.

While the invention has been particularly shown and described asreferenced to the embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope.

What is claimed is:
 1. An extended wear electrocardiography patch withwire contact surfaces, comprising: a flexible backing formed of anelongated strip of stretchable material with narrow longitudinalmidsection evenly tapering inward from a distal end and a proximal end,the elongated strip adherable only to a contact surface defined on eachof the ends; a pair of flexile wires, one of the wires forming anelectrocardiographic electrode, the electrocardiographic electrodeformed by a portion of the one wire that is sewn into the distal end ofthe elongated strip and that is configured for directly contacting thepatient, the one wire continuing back along an axial path through themidsection, another one of the wires forming anotherelectrocardiographic electrode, the electrocardiographic electrodeformed by a portion of the another wire that is sewn into the proximalend of the elongated strip and that is configured for electricallycontacting the patient, each of the electrodes comprising anelectrically conductive area only exposed on the contact surface; and aset of electrical contact pads comprised on the flexible backing andformed by further flexile wires, one or more of the pads of the setconnected to the electrodes and configured to interface the electrodeswith an electrocardiography monitor recorder.
 2. An electrocardiographypatch in accordance with claim 1, further comprising: a non-conductivereceptacle securely adhered on one of the ends of the elongated stripopposite the contact surface and formed to removably receive theelectrocardiography monitor recorder; and a battery compartment formedon a bottom surface of the non-conductive receptacle operable to hold abattery for powering the electrocardiography electrocardiography monitorrecorder.
 3. An electrocardiography patch in accordance with claim 2,further comprising: a spring and a clasp securing the battery within thebattery compartment.
 4. An electrocardiography patch in accordance withclaim 2, further comprising: an additional flexile wire sewn into theflexible backing securing the battery within the battery compartment. 5.An electrocardiography patch in accordance with claim 2, wherein thebattery is interfaced to different one or more of the pads of the setand the different pads are configured to interface the battery to theelectrocardiography monitor recorder.
 6. An electrocardiography patch inaccordance with claim 1, further comprising: a layer of insulationmaterial covering at least part of a surface of the flexile wires.
 7. Anelectrocardiography patch in accordance with claim 1, wherein thefurther flexile wires are over-stitched into the flexible backing.
 8. Anextended wear interlaced electrocardiography patch with wire contactsurfaces, comprising: a flexible backing formed of an elongated strip ofstretchable material with narrow longitudinal midsection evenly taperinginward from a distal end and a proximal end, the elongated stripadherable only to a contact surface defined on each of the ends; a pairof flexile wires, one of the wires forming an electrocardiographicelectrode, the electrocardiographic electrode formed by a portion of theone wire that is interlaced into the distal end of the elongated stripand that is configured for directly contacting the patient, the one wirecontinuing back along an axial path through the midsection, another oneof the wires forming another electrocardiographic electrode, theelectrocardiographic electrode formed by a portion of the another wirethat is interlaced into the proximal end of the elongated strip and thatis configured for electrically contacting the patient, each of theelectrodes comprising an electrically conductive area only exposed onthe contact surface; and a set of electrical contact pads comprised onthe flexible backing and formed by further flexile wires, one or more ofthe pads of the set connected to the electrodes and configured tointerface the electrodes with an electrocardiography monitor recorder.9. An electrocardiography patch in accordance with claim 8, furthercomprising: a non-conductive receptacle securely adhered on one of theends of the elongated strip opposite the contact surface and formed toremovably receive the electrocardiography monitor recorder; and abattery compartment formed on a bottom surface of the non-conductivereceptacle operable to hold a battery for powering theelectrocardiography electrocardiography monitor recorder.
 10. Anelectrocardiography patch in accordance with claim 9, furthercomprising: a spring and a clasp securing the battery within the batterycompartment.
 11. An electrocardiography patch in accordance with claim9, further comprising: an additional flexile wire sewn into the flexiblebacking securing the battery within the battery compartment.
 12. Anelectrocardiography patch in accordance with claim 9, wherein thebattery is interfaced to different one or more of the pads of the setand the different pads are configured to interface the battery to theelectrocardiography monitor recorder.
 13. An electrocardiography patchin accordance with claim 9, further comprising: a layer of insulationmaterial covering at least part of a surface of the flexile wires. 14.An electrocardiography patch in accordance with claim 8, wherein thefurther flexile wires are over-stitched into the flexible backing. 15.An extended wear embedded electrode electrocardiography patch with wirecontact surfaces, comprising: a flexible backing formed of an elongatedstrip of stretchable material with a narrow longitudinal midsectionevenly tapering inward from a distal end and a proximal end, theelongated strip adherable only to a contact surface defined on each ofthe ends; a distal electrically conductive adhesive positioned on thedistal end and configured for directly contacting a patient; a proximalelectrically conductive adhesive positioned on the proximal end andconfigured for directly contacting the patient; a pair of flexile wires,one of the wires forming an electrocardiographic electrode by a portionof the wire embedded within the distal electrically conductive adhesiveon the distal end, the one wire continuing back along an axial paththrough the narrow longitudinal midsection, another one of the wiresforming another electrocardiographic electrode by a portion of theanother wire embedded within the proximal electrically conductiveadhesive, wherein the embedded portion of the one wire receiveselectrical potentials of the patient directly from the distalelectrically conductive adhesive and the embedded portion of the anotherwire receives electrical potentials of the patient directly from theproximal electrically conductive adhesive; and a set of electricalcontact pads comprised on the flexible backing and formed by furtherflexile wires, one or more of the pads of the set connected to theelectrodes and configured to interface the electrodes with anelectrocardiography monitor recorder.
 16. An electrocardiography patchin accordance with claim 15, further comprising: a non-conductivereceptacle securely adhered on one of the ends of the elongated stripopposite the contact surface and formed to removably receive theelectrocardiography monitor recorder; and a battery compartment formedon a bottom surface of the non-conductive receptacle operable to hold abattery for powering the electrocardiography electrocardiography monitorrecorder.
 17. An electrocardiography patch in accordance with claim 16,further comprising: a spring and a clasp securing the battery within thebattery compartment.
 18. An electrocardiography patch in accordance withclaim 16, further comprising: an additional flexile wire sewn into theflexible backing securing the battery within the battery compartment.19. An electrocardiography patch in accordance with claim 16, whereinthe battery is interfaced to different one or more of the pads of theset and the different pads are configured to interface the battery tothe electrocardiography monitor recorder.
 20. An electrocardiographypatch in accordance with claim 15, wherein the further flexile wires areover-stitched into the flexible backing.